Category Archives: Noticias

Adv. Synth. Cat. 2025

Combined Gold and Photoredox Catalysis: Synthesis of 3-Alkenyl-2H-Indazoles from 2-Alkynylazobenzenes

Clara Mañas, Estíbaliz Merino*

We disclose the intramolecular synthesis of 3-alkenyl-2H-indazoles from 2-alkynylazobenzenes, promoted by a dual catalysis using AuCl3 and a ruthenium photocatalyst under visible light irradiation. This reaction proceeds through hydroamination of the alkynyl fragment. The yields are influenced by electronic factors. Control experiments suggest that both radical and polar mechanisms operate in parallel. This transformation involves C−N bond formation and a 1,2-hydride shift. Additionally, derivatization was performed to demonstrate the versatility of this methodology..

Adv. Synth. Cat. 2025
DOI: 10.1002/adsc.202400990

J. Org. Chem. 2024 (Featured article in Synfacts)

Copper-Catalyzed Hydroamination of 2-Alkynylazobenzenes: Synthesis of 3-Alkenyl-2H-Indazoles

Clara Mañas, Juan Herrero-Bordieu, Estíbaliz Merino*

A copper-catalyzed intramolecular synthesis of 3-alkenyl-2H-indazoles from 2-alkynylazobenzenes is described. The reaction proceeds in a single step via C–N bond formation and a subsequent 1,2-hydride shift, affording products in high yields. DFT calculations suggest the 1,2-hydride shift as the rate-determining step. Further derivatization enables functionalization of the 3-alkenyl-2H-indazoles.

J. Org. Chem. 2024
DOI: 10.1038/10.1021/acs.joc.4c02144

Org. Chem. Front 2024

Shaping cyles with light: a regiodivergent approach to tetracyclic aza-aromatic compounds

Clara Mañas, Belén Ibarra, Estíbaliz Merino*

The development of regiodivergent methods that allow access to different structures from a single substrate through intramolecular processes is crucial for accelerating new molecule discovery, as well as making processes more sustainable and efficient in terms of waste production and economy. In this study, we report a novel regiodivergent cyclization procedure to access two distinct azapolyaromatic regioisomers from 2-alkynylazobenzenes. The key to achieving this regiodivergence lies in the presence or absence of a gold catalyst. The irradiation with visible light of 2-alkynylazobenzenes in the presence of a Ir photocatalyst affords 11H-indolo[1,2-b]indazoles, whereas under similar conditions with AuCl3, indazolo[2,3-a]quinolines are produced. Control experiments and DFT calculations suggest that both transformations operate through different reaction mechanisms: the formation of 11H-indolo[1,2-b]indazoles involves a radical mechanism, whereas the formation of indazolo[2,3-a]quinolines appears to proceed predominantly through a polar mechanism. This transformation enables the one-step conversion of simple 2-alkynylazobenzenes into diverse azapolyaromatic structures via an intramolecular visible light-promoted process, holding significant potential for new nitrogenated heterocycles.

Org. Chem. Front. 2024
DOI: 10.1038/s41929-024-01204-6

ChemCatChem 2024

Au Clusters Catalyze The Disulfide Metathesis Reaction By A Reductive Addition-Oxidative Elimination Mechanism

Belén Lerma-Berlanga, Francesco Orlando, Estíbaliz Merino, Antonio Leyva-Pérez*

A plethora of industrial and academic organic chemical reactions are catalyzed by the well-known oxidative addition-reductive elimination (OARE) mechanism. However, the micro-reversed counterpart, i. e. the reductive addition-oxidative elimination (RAOE) mechanism, has to our knowledge not been reported yet in a catalytic manner. Here we show that a gold cluster can act as homogeneous catalyst capable of triggering a reductive addition step with disulfides, manage the incoming electrons and finally execute an oxidative elimination step, to perform the disulfide metathesis reaction. These findings suggest that not only new organic reactions but also other previously reported processes catalyzed by metal clusters may operate through the RAOE mechanism.

ChemCarChem 2024
DOI: 10.1038/s41929-024-01204-6

Nat. Cat. 2024

News & Views invited article – “Synergystic role for CO”

Estíbaliz Merino

Typically, active acyl intermediates are quenched with nucleophiles to complete carbonylation. Now, a visible-light-induced radical relay enables CO insertion and selective (hetero)aryl group migration without nucleophiles.

Nat. Cat. 2024.
DOI: 10.1038/s41929-024-01204-6

New Master Students join to the group

On March 2025, new students of the Master’s in Drug Discovery (UCM, UAH, CEU) have joined our group. During these months they will be carry out their Master’s Thesis Projects within the Biological Chemistry Group at the University of Alcalá  in the Department of Organic and Inorganic Chemistry:

  • Dulce Contreras Morón
  • Raquel Reyes Ballesteros
  • Nuria Fernández Roca
  • Javier Miñones Ginarte
  • Jacqueline Valencia Esparza
  • Isabel Fuentes López
  • Samuel Guzmán Punzón

During the time with us, they will have access to state-of-the-art facilities and will work alongside experienced researchers and members of the group.

We wish you all a successful and rewarding experience and extend a warm welcome!

 

Alcalá’s Best Patent Award 2024

The University of Alcalá has awarded the Best Patent Award 2024 to two members of the Biological Chemistry Research Group, Dr. David Sucunza and Prof. Juan José Vaquero. The award recognizes their work and the research in the patent: Soluciones para diálisis peritoneal que contienen un flavonoide natural como agente osmótico (WO2024008987).

The patent, registered in collaboration with CSIC, claims for solutions for peritoneal dialysis containing a natural flavonoid as an osmotic agent. The present invention refers to peritoneal dialysis solutions that comprise troxerutin or vitamin P4 as an osmotic agent. The invention also refers to the procedure for preparing said solutions and to the novel use of troxerutin.

Congrats!!

Arch. Pharm. 2024

Identification and study of new NF-κB-inducing kinase ligands derived from the imidazolone scaffold

Francisco Maqueda-Zelaya, Lara Valiño-Rivas, Ana Milián, Sara Gutiérrez, José Luis Aceña, Javier Garcia-Marin,* Mª Dolores Sánchez-Niño, Juan J. Vaquero, Alberto Ortiz*

Arch. Pharm. ASAP
DOI: 10.1021/ardp.20240061

Chronic kidney disease (CKD) is a growing health concern, projected to be a major cause of death by 2040, due to an increasing risk of acute kidney injury (AKI). Systems biology-derived data suggest that the unmet need for an orally available drug to treat AKI and improve CKD outcomes may be addressed by targeting kidney inflammation and, specifically, nuclear factor κB-inducing kinase (NIK), a key signaling molecule that activates the noncanonical nuclear factor κB (NF-κB) pathway. We have prepared and identified a small family of imidazolone derivatives that bind NIK and inhibit the noncanonical NF-κB activation pathway. The introduction of heterocyclic substituents in position 2 of the imidazolone core provides compounds with affinity against human NIK. Three candidates, with best affinity profile, were tested in phenotypic experiments of noncanonical NF-κB activation, confirming that the derivative bearing the 4-pyridyl ring can inhibit the processing of NFκB p100 to NFkB2 p52, which is NIK-dependent in cultured kidney tubular cells. Finally, exhaustive docking calculations combined with molecular dynamics studies led us to propose a theoretical binding mode and rationalize affinity measures, in which the aminopyridine motif is a key anchoring point to the hinge region thanks to several hydrogen bonds and the interaction of heterocyclic rings in position 2 with Ser476 and Lys482. Our result will pave the way for the development of potential drug candidates targeting NIK in the context of CKD.